The board just took a huge dirtnap for about five minutes. But...owing to (for once) being in the right place at the right time, I think I know what happened (and by extension what's been happening when the board periodically falls deep asleep).

I was in the admin panel when the site started seizing up and I had happened to notice the size of the current database, in passing. Then the site went away. When it came back up the database was about 20% smaller (yet all the posts seemed ok).

So--and I apologize for the long explanation but I know some of you wonder aloud about these things--when the board goes belly up sometimes there's a good chance it's in the middle of a periodic, perfectly normal optimization, where it pares itself down, throws out unneeded junk, and generally spruces up. Just go grab a lemonade, come back in five and all should be well.